Mechanisms of Carbon Nanotubes Nanotoxicity and Drug Delivery Systems
R. Sharma, S. Kwon, A. Sharma
Florida State University, US
Keywords: nanotoxicity, carbon nanotube, fullerene
Abstract:Carbon Nanotube (CNT) materials show optical, magnetic, electronic, structural unusual toxicity properties and complicate safety in tissue. In optimized quantities with limited functionality these cages may be drug delivery carriers and display different targeting, increased circulating time, and acceptable functionality as biocompatible properties than bulk materials. We analyzed physical parameters of CNT size, mass, surface area and effect on macrophage action, inflammatory action due to nanotoxicity and mechanisms of reactive oxygen (ROS) induced transepithelial resistance decrease in airway physiological function following exposure of 20% CNT (8 g/mL of CNT) concentrations.The mechanisms of nanotoxicity are known due to surface chemistry of membrane damage, protein denaturation, DNA damage, immune reactivity, surface of Zn, Cd, Se coating and surface charge of polycations on membrane, charge density. We established nanotoxicity of fullerenes: 1.Fullerenes nanotubes showed free radical chemistry, attraction to electrons, antioxidant properties. 2. Some Carbon-60 fullerenes bind to nucleotides, hamper self-repair in double–strand DNA. 3. CNT display high electrical and thermal conductivity, high strength, rigidity. Medical/nonmedical applications suggest occupational, accidental exposure. 4. Fullerens(cages), single wall nanotubes, multiwalled nanotubes show toxicity. CNT produce superoxide anion, lipid peroxidation, cytotoxicity in plants and animals. 5. Uncoated fullerenes in largemouth bass show lipid peroxidation in brain tissue and glutathione depletion in gills. 6. C60 toxicity increases by Poly Vinyl Propylene due to stable charge transfer complexes. 7. THF may pass through blood-brain barrier. Metal catalyst used in nanotube fabrication. 8. More derivatized fullerenes were less toxic, due to low efficiency in ROS generation. 9. CNT showed toxicity effects, dose dependent epitheloid granuloma. 10. At optimized CNT single walled CNT concentrations, low Taxotere quantities encaged inside may target breast tumor tissue more efficiently. 11. Cultured alveolar fibroblasts following exposure of CNTs showed possibility of transplanting CNT encaged fibroblasts. In conclusion, medical/nonmedical applications suggest CNT use with care due to occupational, accidental exposure and nanotoxicity as health concern.